As you say: for me, worst case is i get a better understanding of colour in profiles and pipelines from camera to film out, something that i've tended to just accept before.
EDIT: Frank, i'll look into the LUT Buddy, thanks
Results 21 to 30 of 88
05-03-2012 10:16 AM
- Join Date
- Nov 2006
05-03-2012 11:47 AM
There is also the need to handle highlights while previewing during grading/compositing.
Unless the output color space LUT takes care of this (technically it shouldn't), you would still need to apply some knee and roll-off slope, or they would simply clip (assuming correct expansion to linear, taking the camera roll-off into consideration). Well, maybe on some high contrast, high precision display, they wouldn't. But then they would show banding because of the low preserved resolution in the roll-off zone.
So, in away, you would expand the compressed highlights, then compress them back for preview.
That's all in the case of standard DR transfers where exposure correction in post is not really an option. In log-style transfers (and especially 10-bit or more encoded video) perfect linearization will be helpful because of the ability to correct exposure due to the preserved resolution at the extremes.
05-03-2012 12:50 PM
- Join Date
- Jul 2011
I think you are right if you are working from the assumption that your gradeing software clipped & crushed into legal range without options to avoid that.. but i have not worked with a gradeing / finishing software that does that... So the assumption i work with is that the entire range will be preserved intact, and the need to apply anything to avoid clipping and crushing is not needed.
As to the high contrast high precision display? Every grade A mon i've worked with shows full range. I'm watching a render right now... infront of me is an image at full range, displayed on a 16 foot screen via a Christe 2200 set for P3, and beside my UI is a Sony BVM-OLED, also set to P3.. this is a dark comedy, emphsis on dark...
I can see issues with some video centric editing software that clips/crushes and then trying to grade from that would be hard to impossiable for sure, but again i'm not familiar with software that does that, but if that's the horse that you are rideing, then yea, an input transform to keep the mids fat and the top & bottom spread out makes perfect sense to me.
I have seen this with chase Qt's from FCP, but i always go back to the camera orignals and conform from there, so i don't know where the clip/crush happens.. this seems to be a good case for useing input LUT's like Clog/Slog/LogC etc... and maybe there is something to be gained by creating an input LUT specfic to a PP in an FS100..
i can take a shot of a ChromaDuMonde chart and turn it into a video range LUT designed to be displayed on a 2.35 gamma screen with a 709 color model in a few min, what i can't do tho is turn that 3D 64x64 LUT into a ICC profile, nothing would be crushed or clipped.. i do this to for dalies with shows shot on film, and transfered Dmin/Dmax, pretty much everythign else has mfg provided LUT's or does not need them, again the FS seems to fall into that slot for me.
Last edited by Dermot; 05-03-2012 at 01:12 PM.
05-03-2012 01:12 PM
That's not the point.
I am talking display clipping due to out of (display) range brightness. Not software clipping values. I don't think any 32-bit software clips anything.
Say, you have 12 stops encoded in 8-bits. Because the highlights are rolled and the shadows slightly compressed, your monitor is actually displaying like 8 to 9 stops contrast ratio. If you unroll them to linear taking the correct roll-off slope into consideration the monitor will need to display 12 stops. Well, most monitors won't do that (contrast ratios of 1000:1 - around 10 stops - or lower are typical even for grading monitors, and then I would take the manufacturer specified contrast ratio with a grain of salt). They will simply clip to their highest white level, or will bring the blacks up (unless a curve is applied to accommodate the range into the range of the display). And if a monitor actually displays the extreme highlights without pushing the blacks up, they will show banding due to low resolution above the knee point in the camera encoded video (in 8 bits).
05-03-2012 01:20 PM
I thought I have banding and posterisation in some material, till I got a HP Dreamcolor monitor.
Made a huge difference. Actually some of the problems with red faces and all we had with the FS100, are gone when you look at them on a 709 display.
Magic Bullet has this skin overlay grid in Looks, Cosmo and Mojo. All the time I dialed it in, faces looked like cooked lobster.
Now on the Dreamcolor, they are spot on.
Last edited by Postmaster; 05-03-2012 at 01:27 PM.
05-03-2012 01:23 PM
- Join Date
- Jul 2011
ok i'm spolied, but in the three suites i work inbetween two of them have mon's can display everything that comes out of the 444 spigot, one has a mon that shows 97% of P3, and all of 709.
suite 1 = Christe2200/16' screen & Sony BVM OLED
suite 2 = Dolby 4200
suite 3 = DreamColor
all fed 444 duallink to BMD HDlinkPro with callibration LUTs - nothing is clipped or crushed by the mon, or the signal chain.
I might be fair to question the DreamColor in P3, but in 709 it's on target - the new ones have been reported to be better than the first one's tho.
But the Christe projector, the Sony OLED, and the Dolby reference monitor are rock solid, and their spec's can be taken to the bank - verified by a Hubble probe.
Oh and one more thought.. the Dolby has a ton of menu's - includeing the ablity to set it to display only video legal range and the option to either scale it or clip/crush the signal.. much like running through a legaliser... seems much like what you are thinking?
And yea, i love the Dreamcolor enough to have one at home - amazing piece of kit for so little outlay
Last edited by Dermot; 05-03-2012 at 01:41 PM.
05-03-2012 01:46 PM
@Dermot - I have my Dreamcolor hooked up to the second DVI of my graphic card, so I use it as a secondary monitor.
But actually I want to hook it up to my BM card.
From what I understand, you need to hook it up via HDMI or DisplayPort and feed it progressive RGB, to use the full features.
But the BM cards only output YUV.
When I buy a BM HDLinkPro3D with display port, would that do the trick?
05-03-2012 02:11 PM
- Join Date
- Jul 2011
yes, i own two of them, one of the very first, and a new one..
the older one is on my Avid/Nuke playtime toy at home, it's sends HDSDI to an Aja, and then on to HDMI in.. this one is not used for critical color work tho, i replaced a older Sony LMD230w that started going pink & green at the edges, works really well in 709 mode with the packaged OneEye callibration... could be used for mastering without a doubt.
The new one is on a DS editing & finishing system, dualLink out to a BMD HDlinkPro, then displayPort in, this one is in native, and we use a Hubble probe to create pair of LUT's to load into the BMD to choke the monitor's native down to 709 or P3 depending on what we are working on... this maachine is mainly usd for commericals & music video's, but some times i've graded films in that room when scheduales collide
The DreamColor is surpriseingly good in P3, and spot on in 709 this way... full 30bit color top to tail.
I'd get the packaged probe and callibration for it.. that's where it really turns into a fantastic deal.
I'm a fan boy...
and hummm... i've not really had an issue with skintones on my FS, but always monitor on the DreamColor/Dolby/Christe/Sony.. never really see anything on a consumer screen... i wonder how much of the issues are monitoring? I remember on teh first thread you posted about your looks we discussed this a bit...
Last edited by Dermot; 05-03-2012 at 02:18 PM.
05-03-2012 02:22 PM
To use the dreamcolor as a video monitor it needs a rgb true progressive signal to use the on board colour management. If the box cross coverts yuv to rgb it'll probably only output 720p as progressive.
There's a Gefen box that outputs a true 1080p progressive frame that HP recommend.
Last edited by Nirv; 05-03-2012 at 02:31 PM.
05-03-2012 02:47 PM
- Join Date
- Jul 2011
Both the BMD & the Aja are working fine here @ 1080 + YUV.